In medicine, a prodrome is an early symptom indicating the development of a disease, or indicating that a disease attack is imminent. For example fever, malaise, headache and anorexia (lack of desire to eat) are part of the prodrome for the mumps.

A prodrome for schizophrenia is the period of decreased functioning that is postulated to correlate with the onset of psychotic symptoms. The concept has been reconsidered as the pathways to emerging psychosis have been investigated since the mid-1990s.[1] One example of the international paradigms aimed at researching the prodrome is the North American Prodrome Longitudinal Study (NAPLS). This study is concerned with brain development, hormones, and neuropsychological functions that may play a role in risk for and prevention of mental illness in young adulthood. The term at risk mental state is sometimes preferred, as a prodromal period cannot be confirmed unless the emergence of the condition has occurred. (Also see early psychosis.)

Prodrome, or psychosis risk syndrome as it is also known, is a proposed syndrome to be used in the DSM-V (2013) of psychiatry.[2][3] It is also defined as "the aura that precedes a psychotic break by up to two or three years."[3] Patients with this condition "still have 'insight' - a pivotal word in psychiatric literature, indicating that a patient can still recognize an altered worldview as a sign of illness, not revelation."[3] Prodrome is also sometimes called "attenuated psychotic symptoms syndrome."[4] Chairman of the DSM-IV Task Force, Allen Frances, has criticised the concept of Psychosis Risk Syndrome on the grounds of a high rate of inaccuracy, the potential to stigmatize young people given this label, the lack of any effective treatment, and the risk of children and adolescents being given dangerous antipsychotic medication.[5]

About one third of patients with prodrome are diagnosed with schizophrenia or other psychosis in a few years. In the North American Prodrome Longitudinal Study, researchers found that 35 percent of "patients had a psychotic break within two and a half years of enrolling at a clinic."[3] 65 percent "found that their symptoms passed or plateaued."[3] A psychotic break is made statistically more likely (43% vs. 35%) if the patient abuses certain drugs.[3]